Topic: To which bitrate should I transcode 320 kbps MP3s? Will it be audible? (Read 2889 times)previous topic - next topic

To which bitrate should I transcode 320 kbps MP3s? Will it be audible?

10 February, 2013, 06:51:18 PM

Hi guys, considering that I have no CD's for my music, is there a way to take my music library of mostly 320 kbps MP3's (7.6gb) and make them smaller without a large decrease in sound quality?

I'm thinking of taking my all my music and consolidating it by converting them to 256 kbps or even 192 kbps MP3's, will there be a drastic change in sound quality? I'm not an audiophile but I have decent IEM's and I listen to music a lot.

Firstly, try MP3packer to see whether you can shrink any significant size off your files without transcoding them.

As for the format, the usual answer applies: there may or may not be an audible difference to you, and other people have no way of knowing which of those possibilities will apply, as you are the one who will be listening to the resulting files. Transcoding will always degrade the signal further in a theoretical sense, but whether that degradation will be audible to you is an open question that only you can answer. Others can offer their experiences, but that’s really no substitution for your own.

Still, others can post their thoughts if they want; perhaps they have more specific answers than me.

is there a way to take my music library of mostly 320 kbps MP3's (7.6gb) and make them smaller without a large decrease in sound quality?

Transcoding MP3 to MP3 is likely not a good idea. 7.6 GB fits an 8 GB pen drive or mp3 player, how much would you even save to get down to a 4 GB one?

If just a small reduction in size is good enough for you, then mp3packer with the -z option repacks your mp3s without decoding/encoding. You can maybe get your 320's down to 300 completely losslessly (however, if they were created with dodgy encoders, you may lose non-conformal information ... sometimes gaplessness). http://wiki.hydrogenaudio.org/index.php?ti...er#WinMP3Packer

My two cents says that while it is true that no one else can say what you will encounter, sound wise, the majority of people will not be able to tell any difference from the 320 CBR originals by transcoding once to a high quality alternate.

V0 VBR will use 320 kbps whenever it is necessary to achieve the maximum mp3 quality and fewer bits when that quality can be achieved with less. It depends on the music, but saving 20% to 30% over 320 CBR seems common.

V2 VBR will also sound no different to most people. That can save around 15% to 20% more space than using V0.

While c320 is indistinguishable from lossless, it isn't the same signal. The minute differences that you currently don't hear might be amplified when you reencode your music, but I can't tell you how much. Personally I'd never do it, but perhaps you can try it with a few tracks and do some tests to find out how it works for you. I think if 192kbps is normally your optimal bitrate then you may need to take a safe margin and reencode 320kbps to 256kbps instead, but I might be totally wrong about that.

By the way, I do agree with the other comments that the small gain in efficiency is probably not worth it.